The invention relates to a mortar fuse comprising a fan wheel, a generator for the firing energy, a safety device, a fuse device and a double pin as a release device for the fan wheel and the safety device.
The usual mortar fuses have a fan wheel generator which, by means of the fan wheel which rotates in the flow of air, serves to generate the energy for the fuse and to drive the safety device. Fan wheel generators of that kind suffer from the disadvantage that the energy generated is dependent on the speed of rotation of the fan wheel generator, which can fall to zero at the apogee of the trajectory of the mortar shell. That can result in an energy failure or at least adverse effects in terms of reliability of the fuse. A further problem is that the fan wheel can ice up during the flight and come to a stop, also with the problem of energy failure.
The object of the present invention is to propose a highly reliable mortar fuse in which the energy supply of the fuse does not depend on continuous rotation of the fan wheel.
To attain that object, the invention proposes that there is provided an activatable battery which can be brought into operation by an activation wheel driven along a path of travel by the fan wheel. The activation wheel includes a magnetic material, and a coil is disposed adjacent the path of travel. Electric energy is generated in the coil as the magnetic activation wheel passes thereby.
The invention is therefore based on the point that the use of a per se known activatable battery during flight provides for activation of an activation wheel driven by the fan wheel, with a predetermined time delay between launch of the projectile and attainment of the actuation position. Depending on the respective type of battery used, activation again requires a certain period of time before the battery is fully operational. It is at the latest from that moment in time that the speed of rotation of the fan wheel is no longer an important consideration in terms of operability of the fuse.
In accordance with a development of the invention, to produce the time of activation of the battery, it is provided that the activation wheel can be displaced along a spiral on the shaft of the rotating fan wheel and can be brought into contact with the activatable battery.
In a development of the invention, it has been found particularly desirable that the activatable battery comprises a battery container with the battery cells and an acid container which is directly adjacent but separate therefrom, which acid container can be pierced by the activation wheel whereby acid flows into the battery container.
In accordance with a further configuration of the invention, to increase the fail-safe nature of the fuse, it is provided that the activation wheel has a magnet which, upon rotation thereof, moves past a coil and generates energy.
That energy serves during the activation phase of the battery to supply power to the fuse and in particular serves for the supply of energy for a counter which controls the time function of the fuse.
Finally, a further configuration of the invention provides that there is an emergency power supply which includes one or more capacitors and which cooperates with the activation wheel and which ensures operation of the counter in the event of a possible power failure in respect of the battery. The emergency power supply can also be used when using a fan wheel generator.